This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Our research was centered on using structure-based analysis to investigate enzymes involved in the biosynthesis of bisindole natural products. Our goal was to determine the structures of key enzymes in the biosynthetic pathways. We focused specifically on rebeccamycin and violacein biosynthesis, and we targeted the enzymes RebC, VioE, and VioD for structural investigations.